Senate Majority Leader Harry Reid doesn't think much of the ads that have aired this cycle from Americans for Prosperity, a group close to billionaire libertarian industrialists Charles and David Koch. "All of them are untrue," the Nevada Democrat said in February.

In the slightest of backpedals, he amended that statement later. "I can't say that every one of the Koch brothers' ads are a lie, but I'll say this … the vast, vast majority of them are," Reid said.

But in trying to turn the tables on Americans for Prosperity — which has spent millions to help Republicans win control of the Senate in the 2014 midterm elections — Democrats have struggled with accuracy, too.

The overwhelming majority of ads from Americans for Prosperity have earned rulings of Mostly False or worse from PolitiFact. But the Senate Majority PAC, a super PAC fighting to keep Democrats in power, has not fared much better, earning two Mostly False and two False ratings in four recent fact-checks.

Two of those ads ran in Louisiana, where Democratic Sen. Mary Landrieu faces a tough re-election fight. Both ads attacked Rep. Bill Cassidy, R-La., by tying the GOP frontrunner to the Koch brothers and Americans for Prosperity.

In each case, the supporting evidence for the claim was weak.

For example, one ad (correctly) noted that Americans for Prosperity opposed an act to lower flood insurance costs for coastal areas, a big issue in Louisiana. But the Senate Majority PAC then said Cassidy would carry water for the Koch brothers in the Senate.

"The out-of-state billionaire Koch brothers funded the fight to let flood insurance premiums soar, helping the insurance companies and cut off hurricane relief for Louisiana families," the ad said. "Now they're spending millions to buy a Senate seat for Bill Cassidy so he can fight for them. If the Kochs and Cassidy win, Louisiana loses."

Connecting Cassidy to the Koch brothers on that issue surprised us, since Cassidy helped shepherd the flood relief bill to passage in the House. In fact, the measure was officially known as the "Grimm-Cassidy substitute amendment." Senate Majority PAC earned a Mostly False for that one.

Another ad claimed the Koch brothers were supporting Cassidy to "protect companies that ship our jobs overseas." The evidence Senate Majority PAC provided reminded us of the game Six Degrees of Kevin Bacon. They backed up the claim with a complex chain of support linking the Koch brothers to other groups through donations and IRS filings.

We understand and appreciate the importance of following the money in today's campaigns, but after pulling the strings, we found Senate Majority PAC provided little proof that the Koch brothers worked to protect outsourcing. We gave it a False.

Attacks on the Koch brothers are not limited to Senate Majority PAC. Sen. Mark Begich, D-Alaska, hit back against ads that have aired in his home state with a 30-second spot of his own claiming the Koch brothers disrupted the oil industry there.

"They come into our town, buy our refinery, just running it into the ground, leaving a mess," several people in the ad said. "A lot of Alaskans are losing jobs, and I'm definitely concerned about the drinking water."

We couldn't put this one on the Truth-O-Meter because ongoing litigation will ultimately assign blame for the environmental impact.

But there were some important details Begich's ad makers left out. For one, the pollution from the Alaskan refinery started well before Koch Industries' Flint Hills Resources bought the plant (though the pollution continued after the purchase as well).

They also didn't mention that the plant is still operating. About 80 workers were laid off.

A lack of accuracy this campaign cycle from Democratic groups extends beyond their criticisms of the Koch brothers to other claims about Republicans being in bed with big business.

Cotton has never worked for insurance companies nor has he ever served as a consultant for one. While working for the a global consulting firm, he was assigned to help the Federal Housing Authority's multifamily housing program improve insurance offered to lenders who finance apartment buildings. That project actually sought to improve government efficiency.

PolitiFact New Hampshire also slapped a Senate Majority PAC ad with a Mostly False for its attack on Republican Scott Brown, now running for the Senate there.

The ad claimed Brown "delivered for Wall Street, saving big banks $19 billion in taxes." A strange assertion, since Brown was a critical Republican vote in favor of Dodd-Frank, the law passed in response to the big banks' roles in the financial collapse.

Brown did work to negotiate away one tax expected to bring in $19.7 billion over a decade. But the compromise measure to raise the money through other means, which he supported, didn't appease many in the financial sector.

So while Reid is critical of the accuracy in ads from Koch-affiliated groups, Democrats and their allies have responded with several inaccurate attacks of their own. We'll give Reid one thing: It was Mostly True when he suggested the Koch brothers are the richest family in the world (they're actually second).

That aside, so far this election cycle, it appears misinformation is not exclusive to one side of the aisle.